Surface finish and method of making the same



April 5, 1938. c. w. HOFFMAN ET AL SURFACE FINISH AND METHOD OF MAKING THE SAME Filed May 1, 1936 INVENTORS A TTORNEYS and distinct finishing operations.

ous methods sufier the disadvantage that they Patented Apr. 5 1938 UNITED STATES SURFACE FINISH AND METHOD OF MAKING Q THE SALE 1 Charles w. Holman and John 0. Schmidt, Kenmore, and Walter-T. Flowers, Builalo, N. Y., assignors to Pratt & Lambert, Inc., Bulhlo, N. Y.

Application May 1, 1936, Serial No. time I 8 Claims. (01. 91 68) This invention relates to improvements in the finishing of metal, wood and other surfaces.

More specifically, it relates to finishes having multi-toned metallic efiects.

Various methods are known for producing two-' toned finishes and some of these methods produce two-tonedmetallic effcts However, previous methods require the use of two. or more paint products and require at least two separate Some previrequire the use of brittle materials, others require baking. None of the previous methods gives a finish that is readily repaired in case 15 of damage.

' One of the objects of'this-invention is to produce from a single liquid paint a finish having an uneven surface and a multi-toned efiect. Another object of this invention is to produce a finish that closely simulates the appearance of hammered metal. A further object is to provide a finish of this kind which is tough and durable, and which can be produced either with or without baking. A further object is to produce a multi-toned finish which can I readily be repaired in case of damage.

A further object of this invention is to provide an improved method of producing a multi-toned finish. Another object is to provide a method for economically producing a finish simulating the appearance of hammered metal. I

Another object of this invention is to produce paint compositions for producing our improved finishes; also to produce a paint composition, an 35 ingredient of which migrates after application to a surface, so as to produce a multi-toned efiect; also to produce a paint composition, which when spattered on a surface, produces ahammered metal effect. 40 Other objects of the invention will appear in the following description and claims.

Broadly according to this invention, droplets- I 50 thus forming in each area a rim'or edge portion having the color of the finely divided metaL'and a cenfilffil 2 mm or crater having the tone or color of theiranular 11181118116101 dye. The'word tone" is herein used to designate diilerent colors, as well as diilerent huescor shades of the same color.

More specifically, the foregoing objects can be accomplished by incorporating in a thin oleoresinous, resinous or nitrocellulose vehicle afiake metallic powder and a granular pigment, and applying the paint or lacquer by spraying in such a manner that the paint is broken up into small droplets, instead of the fine mist produced by conventional spraying methods, For example,

when using anair pressure spraylgun the droplet spray may be produced by. the use of a special spray head for spattering, or it may be produced u with the usual equipment by greatly reducing the air pressure at the nozzle and using a low pressure in the paint container to force the paint to the nozzle. Spray guns which operate on the principle of centrifugal force may also be employed, if they are operated at speeds iust sufficient to produce droplets of the desired size.

, Best results have been obtained by first applying a scanty coat that does not entirely cover the surface, allowing this coat to set for 15 to 60 seconds and then applying 'a second coat in the same manner, taking care to completely cover Q the surface. However, the hammered eflect may also be produced by a single coat applied sumciently heavy to coverthe entire surface. The hammered appearance develops almost immediately after the paint is applied and the paint may then be air-driai orbaked. When the paint is applied as described above, the droplets discharged from the gun upon'striking the surface spread out to form more or less circular spots or areas which present the appearance of craters surrounded by shallow ridges at the edges thereof.- The metallic powder migrates to and concentrates at the ridges, while color of the craters is modified by the color of the granular pigments. Thus, by selection. of the metal powder and the granular pigments, twotoned effects resembling hammered metal can be produced.

The compositions which may be used for carrying out this process may vary greatlyas to their ingredients and proportions. example, been found that good results can be obtained by using as the clear vehicle either oleoresinous varnishes, alkyd resins oi the oil modified type or clear nitrocellulose lacquers. The vehicles can be chosen so as to be suitable either It has, for

should evaporate more rapidly than in ordinary brushing materials in order to prevent the ridges of the craters from leveling out and also to prevent running or sagging'on vertical surfaces. At the same time, the solvent must evaporate slowly enough to allow the areas formed by the droplets to blend together and to permit the metallic powder collecting in the ridges of the craters before the film has set. Forexam'ple, the preferred viscosity for the finished composition whenthe vehicle is an oleoresinous varnish is to 1 poise. At this consistency, the preferred pressure at the nozzle of the spray gun ranges from 1' to 3 pounds and the preferred pressure on the paint is 5 to 1.0 pounds. Paints of slightly higher viscosity may be used if somewhat higher pressures are employed. We have found that viscosities as high as 3 poises may be used,

in which case the pressure at the nozzle of the gun may be as high as 5 pounds and the pressure on the paint may be as high as 20 pounds. The composition of the paint must be such that it readily wets the surface on which it is applied; otherwise, there is likelihood of the surface being incompletely covered with the paint, so that a continuousfilm will not be obtained.

The metal powders used are in flake form and coated with a fatty acid or soap and may be of the form commercially available. The quantity of metal powder per gallon of finished composition depends upon the particular metal powder employed and also may be varied to produce different effects. It has been found that from of 1% to 35% by weight of metal powder-may be used. The most practical range of metal powder, however, is from about 1% to 5%. While more than 5% can be used, yet because of the relatively high cost of these metals powders, the higher percentages may be avoided,'particularly since very excellent results can be obtained within the range of from 1% to 5%.

The amount ofgranular pigment also varies greatly with the hiding power of the particular pigment employed and with the effect desired, and good results have been obtained by using from of 1% to 40% of granular pigment. The most satisfactory results have been obtained by using from to 12% of pigment.

In the manufacture of the composition a paint containing granular pigment only is first produced. Just before the material is to be used the metallic powder in the form of either dry powder or a paste comprising metallic powder and mineral spirits is mixed into the paint. The whole is then thinned to the proper consistency for application'as defined above.

It is possible to use in place of granular pigments or in connection with granular pigments,

armies through the paint and imparts a brighter appearance to the craters.

Referring to the drawing, the figure represents apanel or portion of a surface, one part of which is uncoated, another part being sprayed with one coat, and the lower part of which has two coats applied thereto. 'In this figure, A represents a panel or portion of a surface. .-The upper part B of this panel is uncoated, the middle part C has a single coat applied thereto, and the lower part D is covered with two coats. It will be noted that a single coat scantily applied,as shown in part C appears to have a series of spots or areas each proof the surface are not covered by the paint. Moreover, there appear crater portions in which the granular pigment predominatesand edge portions to which the metallic powder has migrated. The two coat part D of the panel shows the complete finish produced in accordance with this invention. It will be noted that in this partof the panel a series of areas are formed, each of which is surrounded by a ridge indicated in light color in the drawing. In these ridges, the metal powder has collected, probably because of surface 'duced byone o'r'r'nore droplets and that portions tension between the metallic flakes and thea vehicle, thus leaving in the middle portion of each area a crater containing relatively low concentration of the metallic flakes. Since the droplets which form these areas are fairly close together .and in many cases overlap each other, the ridges containing the metal flakes are of irregular outline and simulate closely a hammered metal surface.

The surface to which our improved finish is applied should be relatively non-porous. If it is desired to apply the finish to a porous surface, such as wall board, plaster, or leather, it is desirable to first apply some material that will satisfactorily seal the surface or overcome the porosity. The surface to be finished should be moderately smooth, although one of the advantages of our improved finish is that minor imperfections in the surface are obliterated by the finish.

It will be obvious from the foregoing that a great variety of effects can be obtained by using different metal powders and granular pigments or dyes of different colors. If a light colored metal powder, such as aluminum powder, is used with a dark colored granular pigment, the rims of the craters will be light andthe centers will be dark,

two, coats of the same liquid composition. However, still other effects can beproduced by using paints of two colors in two successive coats, allowing only the usual very short setting time .between coats. The effects produced in this way havean uneven surface similar to hammered metal, the eflect as to color being quite different than hammered metal but novel and attractive.

Most multi-toned effects are difficult to repair should the workmanship prove defective or should the finish be damaged subsequent to completion. However, in the case of the finish produced by the present invention imperfections are readily corrected by simply applying an additional coat of the original material, either immediately following the customary second coat or following the complete drying of the system.

This extra coat blends into the previous coat so 7 repaired.

ately following the preceding coat and all coats are dried together. The advantages of such a finand economy are obvious The following examples illustrate compositions ishing method from the standpoint of. simplicity which have been successfully used in producing China-wood oil-amberol resin varnish (15- our improved finish, but it is not intended to limit this invention to the examples given, since it will be obvious that innumerable changes can be made to produce various desired effects without departing from this invention. In these examples the proportions stated are by weight.

Example 1' The following paint made with oleoresinous varnish may be used to produce a two-toned effect consisting of blue-grey color contrasted with aluminum powder:

Percent Ultramarine blue 7. 62 Lithopone 4. Lampblack 0. 01

Extra fine lining aluminum powder China-wood oil-limed rosinvarnish (50 gal. length; 45% non-volatile matter)- China-wood oil-amberol resin varnish (15 gal. length; 50% non-volatile matter).. 39.10 Varnish makers 8: painters naphtha.. 37. 00

This paint was applied on a smooth steel panel with a spray gun using a pressure of two pounds at the nozzle and seven pounds .on the paint.

The nozzle was held at a distance of about 18 inches from the surface being coated, and the paint was applied in two thin coats, the first coat having been applied so scantily as to not entirely cover the surface and the second coat was applied within'thirty seconds after the application of the first coat, and in the same manner'as the first. coat. The paint was then baked for fortyfive minutes at a temperature of approximately 250 F.

The resulting finish showed a series of areas varying from th of an inch to %ths of an inch in diameter. The craters of the areas are of a blue color and the edges of these spots are aluminum color.

Example II By means of the following formula, an eflect can be produced which closely simulatesham mered steel, and which may be applied to metal, wood or other surfaces:

Percent -Carbon black 1.00 Extra fine lining aluminum powder.--"

gal. length; 50% non-volatile matter)- China-wood oil-rosin varnish (46.3 gal.

length; 45% non-volatile matter) 12.08 Varnish makers a painters naphtha--- 42. 20 Liquid drier '(cobalt linoleate) 1. 02

mered steel.

This paint is applied to the surface by means of a spatter gun or as described in Example I.

'The finish thus produced dries in air. In this case the craters produced -by the droplets are of 7 guy color and .the rims or edges are of lighter 5 grey, thus producing the appearance of ham- Example 111 The following fo'rniula has been found to pro Emmple V Satisfactory results have also been obtained by using equal parts of a well known nitro-cellulose p Percent Maroon lake 5. '10 15 Bone black 5.90 Lithopone I a 0. 89 -Venus natural copper powder 4. '15

Heat bodied perilla oil 8. 50 China-wood oil-amberol resin varnish (15 g gal. length; 50% non-volatile matter)- 38.10 Varnish makers 8: painters naphtha 26. 10 Toluol 10. 05 Liquid drier (cobalt linoleate) 0.01

This paint is applied to the surface and baked in the same manner as stated in connection with Example I. In this finish the background or interior of the areas formed by the droplets is brown and the edges are of bright copper color.

. Example IV v 35 Thefollowing resinous base composition is used for producing a hammered steel finish: I

' Percent Carbon black 0.51 Antimony mm. -9. 68

Diatomaceous earth. 1. 54 Aluminumbronze paste 1.54 Alkyd resin solution (50% resin, 50% sol- 45 vents) v 47. 94 Mineral spirits...- -4 ,1. 74 Varnish makers and painters naphtha" 19.40 High flash coal tar naphtha 1.22 Xylol' 0. or o Toluoi 1 a 16.36

The aluminum bronze paste specified in the 55 formula comprises about 66% aluminum powder and 34% mineral spirits.

After the paint has been applied to a surface in the manner already described'in connection I with Example I, thecoating is baked for an hour 00 'at 250 F." to produce a hard tough finish of uniform sheen. The foregoing formula *may, of course, be varied by using other colors and other metallic powders or pastes.

black lacquer enameland a thinnertherefor, and 70 adding to this mixture about 8% or amyl acetate. A metallic paste such as aluminum bronze paste is added to the resulting composition to the extentofaboutioapergalloni 'lhismaterialprmb duces a hammered steel effect. The resulting paint will have the-following composition:

Lewisol Resin No. 1 ma maleic acid modifiedv ester gum manufactured by John D. Lewis, Inc.

The aluminum bronze paste specified in the 86 formula comprises about 66% aluminum powder and 34% mineral spirits.

Union oil solvent No. 8 is a volatile petroleum distillate produced by Union Oil Company of California. It is characterized by the presence in substantial amount of aromatic and olefinic constituents and distillation as follows:

Degrees Centigrade Start 96to 98 a 50% 107 to 108 90% r 118 to 120 Dry point 122 to 129 Lacolene is a volatile petroleum distillate produced by R. J. Brown Company. and designed pri- 40 marily as a toluol substitute in nitrocellulose lacquer formulas. It is characterized by rapid, complete evaporation and distillation as follows:

Degrees Centigrade Start 90to 99 90% 111 to 117 Dry point 122 to 129 The words coloring material" as herein used so are intended to designate granular pigments and/or soluble dyes.

. We claimas our invention:

1. A method of finishing a surface to produce a multi-toned metallic effect, which includes 56 spattering upon the surface a paint having a thin vehicle formed with a base selected from a group consisting of oleoresin, resin and nitrocellulose,

and diluted to a viscosity of from one-half to three poises, and containing a coloring material 60 and a metal powder, said spattered paint forming on said surface small connected areas having the metal concentrated in the edge portions thereof.

2. A method of finishing a surface, to produce a multi-toned eflect, which includes spattering 66 upon said surface droplets of a paint having a substantially'transparent vehicle containing coloring material and having metallic flakes in suspension, said paint-having a viscosity from to 3 poises, said droplets spreading on said surface over small areas having said metal in greater concentration at the edges of said areas than at the interior portions thereof.

3. A method .of finishing a surface, to produce a multi-toned effect, which includes projecting upon said surface droplets of a paint having a vehicle containing a granular pigment and having in suspension therein a metal powder, said paint having a viscosity of from to 3 poises, said droplets spreading on said surface over small areas which leave said metal in greater concentration at the edges than at theinterior portions .of said areas.

4. A method according to claim 2, in which the paint is sprayed by air pressure from 1 to 5 pounds per squareinch. v

5. A method of finishing a surface, to produce a multi-toned effect, which includes projecting 'by means of a jet of air at a pressure of from 1 to 5 pounds per square inch a paint having a viscosity of from .to 3 poises, and containing coloring matter and having suspended therein from one-half of one percent to thirty-five percent of a finely divided metal in flake form, delivering said paint to said jet of air at a pressure of from 5 to 20 pounds per square inch, said droplets spreading on the surface over small areas adjoining and overlapping each other, each of saidareas having the finely divided metal in greater concentration at the edges thereof thanin the interior portions.

6'. A method of finishing a surface, to produce a multi-toned effect which includes projecting by means of a jet of air at a pressure of from 1 to 3 pounds per square inch a paint having a viscosity from /2 to ll poise and containing from one-half of one percent-to twelve percent of a granular pigment and from one percent to five percent of a finelydivided metal in fialre form. delivering said paint to said jet of air at a pressure of from 5 to 10 pounds per square inch, said droplets spreading on the surface over small areas adjoining and overlapping each other, each of said areas having the finely divided 'metal in greater concentration at the edges thereof than in the interior portions. I

7. A method of finishing a surface to produce a multi-toned metallic effect, which includes spattering upon the surface a paint I having a thin vehicle formed with a base selected from a group consisting of oleoresin, resin and nitrocellulose, and diluted to a viscosity of from one-half to three poises, and containing a metal powder, said spattered paint forming on said surface small connected areas having the metal concentrated in the edge portions thereof.

8. A method according to claim 1 in which the coloring material is a dye. a

- CHARLES W. HOFFMAN.

JOHN C. SCHMIDT. WALTER T. FLOWERS. 

